Prophase I of meiosis, diakinesis substage in a diploid lily pollen mother cell. Nucleoli are not visible. The 24 chromosomes have condensed, and are each paired with their homolog to form the 12 bivalents. The pinched in regions seen in the bivalents are the locations of crossovers.
Feulgen stained light microscopy image collected using a bright field zeiss microscope, using a 100X, N.A. 1.4 Neuflar lens.